In both closed (e.g. arthroscopic) and open surgeries, it is frequently necessary to form a knot at a surgical site using two lengths of suture emanating from the surgical site, wherein the two lengths of suture must be manipulated with respect to one another at a location remote from the surgical site.
With one known procedure, a "taut-line hitch" knot is formed in the loose ends of the suture at a location remote from the surgical site from which the suture ends emanate, and then the knot is run down the suture ends to the surgical site by pulling with a sawing motion on the appropriate suture ends. A significant drawback to this procedure is that as the appropriate suture end is pulled through the tissue in which the suture is implanted so as to run the knot down to the surgical site, the sawing motion imparted to the suture ends causes the latter to tend to cut and abrade the tissue.
An alternative procedure consists of forming a throw in the suture at a location remote from the surgical site from which the suture ends emanate, running the throw down the length of suture to the surgical site, forming a second throw in the suture at a location remote from the surgical site, running that throw down the length of suture to the surgical site so that it sits atop the first throw, and thereafter repeating the foregoing process as many times as necessary so as to form the desired knot at the surgical site. As used herein, a "turn" consists of two ends of suture which are looped over one another one or more times, a "throw" consists of one or more turns, and a "knot" consists of two or more throws laid on top of one another and tightened so as to lock the two strands of suture relative to one another.
Arthrex Arthroscopy Instruments, Inc. of Black Rock, Conn. manufactures several tools for running a suture throw down suture ends to a surgical site from a location remote from the surgical site. One such tool is identified as the Arthrex Arthroscopy Knot Pusher (Model No. AR-1310). This knot pusher comprises an elongate shaft having an end portion which is inclined slightly with respect to the long axis of the shaft. The end portion includes a bore extending therethrough. After a throw is formed in the suture ends at a location remote from the surgical site from which the suture ends emanate, one of the ends is threaded through the bore in the end portion of the knot pusher. Then the tool is run down the length of that suture end, while maintaining appropriate tension on the suture ends, so as to push the throw toward the surgical site. Once the first throw has been run down the suture lengths to the surgical site, another throw may be formed in the suture ends at a location remote from the surgical site and then run down the suture ends to the surgical site so that it sits atop the first throw. This procedure may be repeated as many times as desired so as to form a knot at the surgical site.
Although the Arthrex Arthroscopy Knot Pusher Model No. AR-1310 device functions satisfactorily under many conditions, it tends to suffer from certain problems which limit its usefulness under certain conditions. First, it is sometimes difficult to thread one of the suture ends through the bore in the end portion of the knot pusher. Second, it can be difficult to maintain tension on the suture ends while simultaneously running the throw down the suture ends with the tool. Third, it can take more time than is desired to run a number of throws down the suture ends to the surgical site using the Arthrex knot pusher. Fourth, it tends to be difficult, if not impossible, to run a two turn throw down suture ends using the Arthrex knot pusher.
Arthrex Arthroscopy Instruments, Inc. manufactures another knot pusher tool identified as Model No. AR-1311. This tool comprises an elongate shaft having a rounded front end, and a pair of holes extending in from the sides of the shaft at an angle and terminating at the front end of the shaft. To use the Model No. AR-1311 tool, a throw is formed in the suture ends emanating from the surgical site. Then, each of the free ends of the suture extending away from the throw is threaded into a corresponding respective one of the holes in the front end of the tool and caused to pass out the end of that hole intersecting the side of the tool. Next, the surgeon grasps the suture ends extending out of the holes in the sides of the tool and applies tension to the suture ends: Thereafter, while maintaining this tensioning of the suture ends, the surgeon urges the tool toward the surgical site by pushing against the rear end of the tool, typically with his or her stomach, thereby causing the tool to run the throw down the suture ends to the surgical site. As the throw is run down to the surgical site, successive portions of the suture ends emanating from the surgical site pass through the holes in the rundown tool. Finally, the rundown tool is extracted from the surgical site, whereby the suture ends pass back through, and ultimately are removed from the holes in the rundown tool. Subsequent throws are run down to the surgical site following this procedure.
Although the Arthrex Model No. AR-1311 functions satisfactorily under certain conditions, it tends to suffer from several problems which limit its usefulness under other conditions. First, it is necessary to thread the suture ends through the inclined holes at the front end of the tool for each throw which is to be run down to the surgical site. Such threading can be time consuming and inconvenient. Second, when braided suture is used to tie adjacent pieces of tissue together, knots or throws formed therein tend to come apart more readily than when the knot or throws are formed in monofilament suture. As such, after the Arthrex tool Model No. AR-1311 has been used to run throws down braided suture to a surgical site, during withdrawal of the tool from the surgical site the action of drawing the suture ends back through the holes in the tool tends to cause the throws at the surgical site to loosen. This loosening is undesirable since it makes it difficult to securely suture tissue with the loosened knot. Third, it tends to be difficult for the surgeon to physically coordinate maintaining tension on the suture ends while simultaneously urging the rundown tool toward the surgical site.
Yet another Arthrex rundown tool is illustrated, although not described, on page 7 of a brochure published by Arthrex Arthroscopy Instruments, Inc. entitled "The Arthrex Grasping Stitcher System". This rundown tool comprises an elongate shaft which apparently has a rounded or convex V-shaped front end, and a pair of axially-extending, diametrically opposed grooves which terminate at the front end of the tool. A ring surrounds and engages the front end of the shaft, whereby the grooves are surrounded by the ring.
This Arthrex tool apparently functions substantially identically to the Arthrex tool Model No. AR-1310 described above, except that each of the suture ends is positioned in a respective one of the elongate grooves and is passed underneath the surrounding ring, rather than being threaded in the holes at the front end of the Arthrex tool Model No. AR-1310. In addition to suffering from the problems described above with respect to the Arthrex tool Model No. AR-1310, the Arthrex tool described in the above-referenced brochure tends to apply pressure directly to the suture throw rather than to the portions of suture immediately adjacent the throw. As a result of this application of pressure, the suture throw may tend to bind as it is run down to the surgical site.